//join() 方法将一个数组（或一个类数组对象）的所有元素连接成一个字符串并返回这个字符串。如果数组只有一个项目，那么将返回该项目而不使用分隔符。
const elements = ['Fire', 'Air', 'Water'];

console.log(elements.join());
// expected output: "Fire,Air,Water"

console.log(elements.join(''));
// expected output: "FireAirWater"

console.log(elements.join('-'));
// expected output: "Fire-Air-Water"

const str = 'The quick brown fox jumps over the lazy dog.';
const words = str.split(" ")
console.log(words)

const str1 = 'The,quick,brown,fox,jumps,over,the,lazy,dog';
const words1 = str1.split(",")
console.log(words1)
